A conventional power supply device for an LED (light emitting diode) module uses a single-stage power factor correction scheme, and generates, based on an alternating current (AC) input voltage of 50 Hz or 60 Hz, a direct current (DC) driving current to drive the LED module. The driving current generally has a relatively large ripple component at 100 Hz or 120 Hz, resulting in flickering of light emitted from the LED module which may cause visual fatigue of a user.